The main purpose of this research project is to determine the basis for differences in circadian curves of plasma cortisol which have been found between normal and glaucomatous populations. To evaluate the role of central neuro-endocrine mechanisms episodic secretion of plasma adrenocorticotropic hormone (ACTH) and cortisol will be studied. The influence of light and dark will also be investigated in relation to episodic secretion of cortisol and ACTH and their correlation with ocular pressure. The clearance of plasma ACTH after an intravenous injection of ACTH will be studied to determine the role of metabolic and other factors in maintaining differences in plasma levels of ACTH between glaucomatous patients and normals. The level of cortisol in lymphocytes will be measured as a possible diagnostic test which could determine those glaucomas and ocular hypertensives who have an increased number of episodes of secretions of plasma cortisol. Finally the effect of cyproheptadine - an anti-serotonin drug which lowers plasma cortisol and ACTH will be evaluated as a possible therapeutic agent in ocular hypertension and glaucoma.